Method of manufacturing a thin film magnetic head

ABSTRACT

When manufacturing a thin film magnetic head, a first magnetic pole and a second magnetic pole are magnetically coupled and face each other in a recording-medium-facing surface. A gap layer is in between the first and second magnetic pole. A thin film coil for generating magnetic flux is also included. A first magnetic layer is formed. A first magnetic pole is then formed on the first magnetic layer so as to be magnetically coupled to part of the first magnetic layer. A first insulating layer is formed with an inorganic material extendedly from a surface of the first magnetic pole opposite to the recording-medium-facing surface to a top surface of the first magnetic layer. The gap layer is formed on the first magnetic pole. Then the second magnetic pole is formed on the gap layer longer than the first magnetic pole. The second magnetic layer is formed so as to be magnetically coupled to part of the second magnetic pole.

This is a division of application Ser. No. 09/220,703 filed Dec. 24,1998, now U.S. Pat. No. 6,317,288.

BACKFGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a thin film magnetic head having atleast an inductive-type magnetic transducer for writing and a method ofmanufacturing the same.

2. Description of the Related Art

Performance improvement in thin film magnetic heads has been sought inaccordance with an increase in surface recording density of a hard diskdevice. A composite thin film magnetic head, which is made of a layeredstructure including a recording head having an inductive-type magnetictransducer for writing and a reproducing head having magnetoresistive(MR) elements for reading, is widely used as a thin film magnetic head.The MR elements includes an anisotropic magnetoresistive (AMR) elementthat utilizes the AMR effect and a giant magnetoresistive (GMR) elementthat utilizes the GMR effect. A reproducing head using an AMR element iscalled an AMR head or simply an MR head. A reproducing head using theGMR element is called a GMR head. The AMR head is used as a reproducinghead whose surface recording density is more than 1 gigabit per squareinch. The GMR head is used as a reproducing head whose surface recordingdensity is more than 3 gigabit per square inch.

In general, an AMR film is made of a magnetic substance that exhibitsthe MR effect and has a single-layered structure. In contrast, most ofGMR films have a multi-layered structure consisting of a plurality offilms. There are several types of mechanisms which produces the GMReffect. The layer structure of a GMR film depends on the mechanism. TheGMR films include a super-lattice GMR film, a spin valve film, agranular film and so on, while the spin valve film is most efficient asthe GMR film which has a relatively simple structure, exhibits a greatchange in resistance in a low magnetic field, and is suitable for massreproduction.

As a primary factor for determining the performance of a reproducinghead, there is a pattern width, especially an MR height. The MR heightis the length (height) between the end of an MR element closer to an airbearing surface and the other end. The MR height is originallycontrolled by an amount of grinding when the air bearing surface isprocessed. The air bearing surface (ABS) here is a surface of a thinfilm magnetic head that faces a magnetic recording medium and is alsocalled a track surface.

Performance improvement in a recording head has also been expected inaccordance with the performance improvement in a reproducing head. It isrequired to increase the track density of a magnetic recording medium inorder to increase the recording density among the performance of arecording head. In order to achieve this, a recording head of a narrowtrack structure in which the width of a bottom pole and a top polesandwiching a write gap on the air bearing surface is required to bereduced to the order of some microns to submicron. Semiconductor processtechnique is used to achieve the narrow track structure.

Another factor determining the performance of a recording head is thethroat height (TH). The throat height is the length (height) of aportion (magnetic pole portion) which is from the air bearing surface toan edge of an insulating layer which electrically isolates the thin filmcoil. Reducing the throat height is desired in order to improve theperformance of a recording head. The throat height is controlled as wellby an amount of grinding when the air bearing surface is processed.

In order to improve the performance of a thin film magnetic head, it isimportant to form the recording head and the reproducing head asdescribed in well balance.

Here, an example of a manufacturing method of a composite thin filmmagnetic head as an example of a thin film magnetic head of a relatedart is to be described with reference to FIGS. 31A and 31B to FIGS. 36Aand 36B.

As shown in FIGS. 31A and 31B, an insulating layer 102 made of, forexample, alumina (aluminum oxide, Al₂O₃ of about 5 to 10 μm in thicknessis formed on a substrate 101 made of, for example, aluminum oxide andtitanium carbide (Al₂O₃.TiC). Further, a bottom shield layer 103 for areproduction head made of, for example, permalloy (NiFe) is formed onthe insulating layer 102.

Next, as shown in FIGS. 32A and 32B, for example, alumina of about100˜200 nm in thickness is deposited on the bottom shield layer 103 toform a shield gap film 104. Then, an MR film 105 of tens of nanometersin thickness for making up the MR element for reproduction is formed onthe shield gap film 104, and photolithography with high precision isapplied to obtain a desired shape. Next, a lead terminal layer 106facing the MR film 105 is formed by lift-off method. Next, a shield gapfilm 107 is formed on the shield gap film 104, the MR film 105 and thelead terminal layer 106, and the MR film 105 and the lead terminal layer106 are buried in the shield gap layers 104 and 107. Next, a topshield-cum-bottom pole (called bottom pole in the followings) 108 ofabout 3 μm in thickness made of, for example, permalloy (NiFe), which isa material used for both of a reproduction head and a recording head, isformed on the shield gap film 107.

Next, as shown in FIGS. 33A and 33B, a write gap layer 109 of about 200nm in thickness made of an insulating layer such as an alumina film isformed on the bottom pole 108. Further, an opening 109 a for connectingthe top pole and the bottom pole is formed through patterning the writegap layer 109 by photolithography. Next, a pole tip 110 is formed withmagnetic materials made of permalloy (NiFe) and nitride ferrous (FeN)through plating method, while a connecting portion pattern 110 a of thetop pole and the bottom pole is formed. The bottom pole 108 and a toppole layer 116 which is to be described later are connected by theconnecting pattern 110 a and so that forming a through hole after CMP(Chemical and Mechanical Polishing) procedure which is to be describedlater becomes easier.

Next, as shown in FIGS. 34A and 34B, the write gap layer 109 and thebottom pole 108 are etched about 0.3˜0.5 μm by ion milling having thepole tip 110 as a mask. By etching the bottom pole 108, a trim structureis formed. As a result, widening of effective write track width can beavoided (that is, suppressing widening of magnetic flux at the bottompole when data is being written). Next, after an insulating layer 111 ofabout 3 μm, made of, for example, alumina is formed all over thesurface, the whole surface is flattened by CMP.

Next, as shown in FIGS. 35A and 35B, a first layer of a thin film coil112 for inductive-type recording heads made of, for example, copper (Cu)is selectively formed on the insulating layer 111 by, for example,plating method. Further, a photoresist film 113 is formed in a desiredpattern on the insulating layer 111 and the thin film coil 112 byphotolithography with high precision. Further, a heat treatment ofdesired temperature is applied for flattening the photoresist film 113and insulating between the thin film coils 112. Likewise, a second layerof a thin film coil 114 and a photoresist film 115 are formed on thephotoresist film 113, and a heat treatment of desired temperature isapplied for flattening the photoresist film 115 and insulating betweenthe thin film coils 114.

Next, as shown in FIGS. 36A and 36B, a top pole yoke-cum-top pole layer(called a top pole layer in the followings) 116 made of, for example,permalloy, which is a magnetic material for recording heads, is formedon the top pole 110, the photoresist films 113 and 115. The top polelayer 116 has a contact with the bottom pole 108 in a position rear ofthe thin film coils 112 and 114, and is magnetically coupled to thebottom pole 108. Further, an over coat layer 117 made of, for example,alumina is formed on the top pole layer 116. At last, a track surface(air bearing surface) of recording heads and reproducing heads is formedthrough a slider machine processing, and a thin film magnetic head iscompleted.

In FIGS. 36A and 36B, TH represents the throat height and MR-Hrepresents the MR height. Further, P2W represents the track (magneticpole) width.

As an factor for determining the performance of a thin film magnetichead, there is an apex angle as represented by θ in FIG. 36A besides thethroat height TH and the MR height MR-H and so on. The apex angle is anangle between a line connecting the corner of a side surface of thetrack surface of the photoresist films 113, 115 and an upper surface ofthe top pole layer 116.

To improve the performance of a thin film magnetic head, it is importantto form the throat height TH, the MR height MR-H and the apex angle θ asshown in FIG. 36A precisely.

Especially these days, for enabling high surface density writing, thatis to form a recording head with a narrow track structure, submicronmeasurement of equal to or less than 1.0 μm is required for the trackwidth P2W. For that, a technique for processing the top pole tosubmicron using a semiconductor processing technique is required.Further, utilizing magnetic materials which has high saturation magneticflux density for the magnetic pole is desired following theimplementation of the narrow track structure.

Here, the problem is that it is difficult to precisely form the top polelayer 116 on a coil area (apex area) being protruded like a mountaincovered with photoresist films (for example, the photoresist films113,115 shown in FIG. 36A).

As a method of forming the top pole, frame plating method, shown in, forexample, Japanese Patent Application laid-open in Hei 7-262519, is used.When the top pole is formed by the frame plating method, first, a thinelectrode film made of, for example, permalloy is formed all over theapex area. Next, photoresist is applied on it, and by patterning itthrough photolithography, a frame for plating is formed. Further, thetop pole is formed through plating method having the electrode filmformed earlier as a seed layer.

By the way, the apex area and other areas have, for example, equal to ormore than 7 to 10 μm differences in heights. If the film thickness ofthe photoresist formed on the apex area is required to be equal to ormore than 3 μm, a photoresist film of equal to or more than 8 to 10 μmin thickness is formed in the lower part of the apex area since thephotoresist with liquidity gathers into a lower area. To form a narrowtrack as described, a pattern with submicron width is required to beformed with a photoresist film. Accordingly, forming a micro patternwith submicron width with a photoresist film of equal to or more than 8to 10 μm in thickness is required. However, it has been extremelydifficult.

Further, during an exposure of photolithography, a light for theexposure reflects by an electrode film made of, for example, permalloy,and the photoresist is exposed also by the reflecting light causingdeformation of the photoresist pattern. As a result, the top pole cannot be formed in a desired shape and so on since side walls of the toppole take a shape of being rounded. As described, with a related art, ithas been extremely difficult to precisely control the track P2W and toprecisely form the top pole so as to implement a narrow track structure.

For the reasons described above, as shown in a procedure of an exampleof a related art in FIGS. 33A and 33B˜36A and 36B, a method ofconnecting the pole tip 110 and a yoke area-cum-top pole layer 116 afterforming a track width of equal to or less than 1.0 μm with the pole tip110 which is effective for forming a narrow track of a recording head,that is, a method of dividing the regular top pole into the pole tip 110for determining the track width and the top pole layer 116 which becomesthe yoke area for inducing magnetic flux is employed (Ref. JapanesePatent Application laid-open Sho 62-245509, Sho 60-10409). By dividingthe top pole into two as described, the pole tip 110 can befine-processed to submicron width on a flat surface of the write gaplayer 109.

However, there still exists problems as follows regarding the thin filmmagnetic head.

(1) First, in the magnetic head of a related art, the throat height isdetermined in an edge of a further side from the track surface 118 ofthe pole tip 110. However, if the width of the pole tip 110 becomesnarrower, a pattern edge is formed being rounded by photolithography. Asa result, the throat height which is required to have a highly precisemeasurement becomes inhomogeneous, which leads to a state where thethroat height and the track width of magnetoresistive element becomesunbalanced in a procedure of processing and polishing the track surface.For example, when 0.5˜0.6 μm of the track width is needed, a problem inwhich an edge of a further side from the track surface 118 of the poletip 110 is shifted from the throat height 0 position to the tracksurface 118 side and writing gap is widely opened, often causing aproblem in which writing of recording data can not be performed.

(2) Next, as described above, in the magnetic head of a related art, itis not required to fine-process the top pole layer 116 as precise as thepole tip 110, since the track width of the recording head is determinedby the pole tip 110 of the divided top pole. However, since the locationof the top pole layer 116 is determined in the upper area of the poletip 110 by positioning of photolithography, if both are largely shiftedto one side when looking at the structure from the track surface 118(FIG. 36A) side, so-called side write for performing writing on the toppole layer 116 side occurs. As a result, the effective track widthbecomes wider and a problem that writing is performed in a region otherthan the originally designated data recording region in a hard diskoccurs.

Further, when the track width of the recording head becomes extremelyfiner, especially equal to or less than 0.5 μm, a process precision ofsubmicron width is required in the top pole layer 116. That is, if themeasurement difference in a lateral direction of the pole tip 110 andthe top pole layer 116 is too significant when looking at it from thetrack surface 118 side, as described above, a side write occurs and aproblem that writing is performed in a region other than the originallydesignated data recording region in a hard disk occurs.

As a result, not only the pole tip 110 but also the top pole layer 116is required to be processed to the submicron width, however, it isdifficult to perform fine-process of the top pole layer 116 since thereis a significant difference in heights as described above in the apexarea under the top pole layer 116.

(3) Further, in the magnetic head of a related art, there is a problemthat it is difficult to shorten a yoke length. That is, the narrower thecoil pitch becomes, the easier the achievement of a head with short yokelength becomes and, especially, a recording head with a high frequencycharacteristics can be formed. However, when the coil pitch is madeindefinitely small, the length of outer periphery end of the coilbecomes a main factor for preventing the yoke length from shortening forthe position of the throat height 0. The yoke length can be made shorterwith two-layered coil than one-layered coil so that most of therecording heads for high frequency employ the two-layered coil. However,in the magnetic head of a related art, after forming a first layer ofcoil, a photoresist film of about 2 μm is formed in order to form aninsulating film between the coils. As a result, a small apex area havinga rounded shape is formed in the outer peripheral end of the first layerof the coil. Next, a second layer of the coil is to be formed on it,however, etching to have a seed layer can not be performed in the slopeof the apex area causing the coil to short-circuit, which makes itimpossible to form the second layer of the coil. Accordingly, the secondlayer of the coil needs to be formed on a flat area. When the slope ofthe apex is 45˜55°, if the thickness of the coil is 2˜3 μm and thethickness of the insulating film between the coils is 2 μm, 8˜10 μmwhich is twice of 4 ˜5 μm, (the distance from the contact area of thetop pole and the bottom pole to the outer peripheral end of the coilalso needs to be 4˜5 μm) the distance from the outer peripheral end ofthe coil to the vicinity of the throat height 0 position is needed. Thishas been the main factor for preventing the yoke length from reducing.For example, when forming two layers of coils with 11 turns withline/space being 1.0 μm/1.0 μm, suppose the first layer is 6 turns andthe second layer is 5 turns, then, the length of the coil of the yokelength is 11 μm. Here, since 8˜10 μm is required in the apex area of theouter peripheral end, reduction of the yoke length to equal to or lessthan 19˜21 μm is impossible. This has prevented the high frequencycharacteristics from improving.

SUMMARY OF THE INVENTION

The invention is presented to solve these problems. The first object isto provide a thin film magnetic head which can precisely control thethroat height in the recording head and a method of manufacturing thesame.

Further, the second object is to provide a thin film magnetic head,which can fine-process the submicron width of the top pole layer inaddition to the precise control of the throat height, whosecharacteristic of the recording head is improved, and a method ofmanufacturing the same.

Further, the third object is, in addition to the precise control of thethroat height, to provide a thin film magnetic head which can reduce theyoke length of the recording head and whose high frequencycharacteristic is improved, and a method of method of manufacturing thesame.

A thin film magnetic head of the invention has at least two magneticlayers which includes a first magnetic pole and a second magnetic polebeing magnetically connected to each other, part of sides of whichfacing a recording medium face each other through a write gap layer, andone or more than two layers of thin film coil for generating magneticflux. The thin film magnetic head comprises a first magnetic layer, afirst pole formed being divided from the first magnetic layer, while theopposite surface of a neighboring surface of the write gap layer beingmagnetically coupled to part of region of the first magnetic layer, asecond magnetic layer including the second magnetic pole, and aninsulating layer formed with inorganic materials, and formed extendedlyat least from a surface of the first magnetic pole which is opposite ofa side facing the recording medium to one of the surfaces of the firstmagnetic layer.

In the thin film magnetic head of the invention, as the first pole isformed to be divided from the first magnetic layer and to have convexshape against the first magnetic layer, the insulating layer made of aninorganic material is formed adjacent to the first magnetic pole.Accordingly, a phenomenon (protrusion) in which a track pole (top poleor pole tip) sticks out to ABS by thermal expansion generated duringoperation on the hard disk can be suppressed to minimum. Further, thethroat height of the recording head portion is precisely determined bymaking the length of the first magnetic pole from the surface facing therecording medium towards inner direction equal to the length of thethroat height of the recording head. Further, by burying the thin filmcoil in a region in which the insulating layer is formed, the step ofthe apex area including the coil becomes lower comparing to that of arelated art. As a result, when forming the second magnetic pole byphotolithography technique, difference in the thickness of photoresistfilm on the top and the bottom of the apex area is decreased.Accordingly, micronizing the submicron measurement of the secondmagnetic pole can be achieved.

A thin film magnetic head of the invention can be further achieved withthe embodiments in the followings in addition to the structuresdescribed above.

That is, in the thin film magnetic head of the invention, the lengthfrom a surface of the first magnetic pole facing the recording medium ispreferable to be equal to the length of the throat height of therecording head. Further, a structure in which at least part of afilm-thickness direction of, at least, a layer of the thin film coil isformed to be placed in a region where the insulating layer is formed ispreferable.

Further, in the thin film magnetic head of the invention, the insulatinglayer may include a first insulating layer being extendedly formed froma surface of the first magnetic pole which is opposite of a side facingthe recording medium to one of a surface of the magnetic layer, and asecond insulating layer being formed at least between windings of thethin film coil. Further, a surface of the insulating layer which isopposite of a neighboring surface of the first magnetic layer may beformed to be the same surface substantially as a surface of the firstmagnetic pole which is opposite of a neighboring surface of the writegap layer.

Further, in the thin film magnetic head of the invention, the secondmagnetic pole may be formed being divided from the second magneticlayer, and may be magnetically coupled to the second magnetic layer in,at least, part of a surface of an opposite side of a neighboring surfaceof the write gap layer.

Further, in the thin film magnetic head of the invention, width of thefirst magnetic pole along a surface facing the recording medium may beformed to be wider than width of the second magnetic pole.

Further, in the thin film magnetic head of the invention, the secondmagnetic pole may be formed in the same length as the first magneticpole from the surface facing the recording medium to the inner side.

Further, the length of the second magnetic pole may be formed longerthan that of the first magnetic pole. With such a structure, the contactarea of the second magnetic pole and the second magnetic layer can besufficiently maintained and magnetic coupling of the second magneticpole and the second magnetic layer be better performed.

Further, the thin film magnetic head of the invention may comprise afirst connecting portion formed adjacent to the first magnetic layer inthe vicinity of an edge of the second magnetic layer which is anopposite side of a side facing the recording medium, and a secondconnecting portion formed adjacent to the second magnetic layer in aplace facing the first connecting portion. Further, the areas of thefirst connecting portion and the second connecting portion facing eachother may be different. Preferably, the area of the second connectingportion is formed larger than that of the first connecting portion.

Further, in the thin film magnetic head of the invention, the secondmagnetic layer is preferably formed in a place which is recessed from asurface facing the recording medium.

Further, in the thin film magnetic head of the invention, the firstinsulating layer may be formed along surfaces of both sides of the firstmagnetic pole except for an edge surface of a side facing the recordingmedium.

Further, in the thin film magnetic head of the invention, the whole partof film-thickness direction of the thin film coil may be formed in aregion where the first insulating layer is formed. Further, a surface ofthe thin film coil which is opposite of a neighboring surface of thefirst insulating layer may be formed to be substantially the samesurface as a neighboring surface of the first magnetic pole with thewrite gap layer.

Further, in the thin film magnetic head of the invention, the secondinsulating layer may be formed to be substantially the same surface as aneighboring surface of the first magnetic pole with the write gap layer.

Further, in the thin film magnetic head of the invention, a surface ofthe second magnetic layer, which is on the opposite side of the facingsurface of the write gap layer, may be flat. Further, the thin film coilmay be buried in the insulating layer and, the surface of the secondmagnetic layer, which is in the opposite side of the facing surface ofthe write gap layer may be made flat.

Further, in the thin film magnetic head of the invention, one of thesurfaces of the write gap layer may be formed to cover the secondinsulating layer and the thin film coil. Further, a third magnetic layermay be, at least, formed extendedly from a surface of the secondmagnetic pole which is opposite of a side facing the recording medium toother surface of the write gap layer. Further, the thin film magnetichead may have a structure, which comprises at least one layer of thinfilm coil formed being covered with other insulating layer which isdifferent from the first to the third insulating layers, between thethird insulating layer and the second magnetic layer. Further, the thirdinsulating layer and other insulating layer may be formed to besubstantially the same surface with a surface of the second magneticpole which is opposite of a neighboring surface of the write gap layer.

Further, in the thin film magnetic head of the invention, the width ofthe second magnetic pole which is on the opposite-surface side of a sidefacing the recording medium may be formed to be wider than the width ofa side facing the recording medium. A surface of the first magnetic polewhich is opposite of a side facing the recording medium may be formed toincline towards the first magnetic layer.

Further, the thin film magnetic head of the invention may be formed tocomprise a magnetoresistive element for reading out.

A method of manufacturing a thin film magnetic head of the inventionincludes: a step of forming a first magnetic pole on the first magneticlayer so as to be magnetically coupled to part of a region of the firstmagnetic layer after forming the first magnetic layer; a step of formingan insulating layer with inorganic materials extendedly, at least, froma surface of the first magnetic pole which is the opposite of a sidefacing the recording medium to one of the surfaces of the first magneticlayer; and a step of forming a second magnetic layer including thesecond magnetic pole, at least, after forming a write gap layer on thefirst magnetic pole.

In a method of manufacturing a thin film magnetic head of the invention,the first magnetic pole is formed having a convex shape against thefirst magnetic layer, and an insulating layer made of an inorganicmaterial is formed adjacent to the first magnetic pole. As a result, thethroat height can be determined precisely by making the length of thefirst pole from the facing surface of the recording medium to the innerdirection equal to the length of the throat height of the recordinghead.

A method of manufacturing a thin film magnetic head of the invention canbe further achieved with the embodiments in the followings in additionto the structures described above.

That is, a method of manufacturing a thin film magnetic head of theinvention may include a step in which at least part of a film-thicknessdirection of, at least, a layer of the thin film coil is formed to beplaced in a region where the insulating layer is formed.

Further, a method of manufacturing a thin film magnetic head of theinvention may include a step of forming insulating layers extendedlyfrom a surface of the first magnetic pole which is opposite of a sidefacing the recording medium to one of the surfaces of the first magneticlayer, and a step of forming a second insulating layer, at least,between windings of the thin film coil.

Further, a method of manufacturing a thin film magnetic head of theinvention may include a step of flattening a surface of the secondinsulating layer which is the opposite of a neighboring surface of thefirst magnetic layer so as to make it substantially the same surface asa surface of the first magnetic pole which is the opposite of aneighboring surface of the write gap layer.

Further, a method of manufacturing a thin film magnetic head of theinvention may include a step of forming the second magnetic layer so asto be magnetically coupled to, at least, part of the first magnetic poleafter forming the second magnetic pole on the write gap layer.

Moreover, the length of the second magnetic pole may be longer than thatof the first magnetic pole. Further, in the vicinity of the edge of thesecond magnetic layer, which is in the opposite side of the facing sideof the recording medium, the thin film magnetic head may comprise thefirst connecting portion formed adjacent to the first magnetic layer,and the second magnetic layer formed adjacent to the second magneticlayer in a position facing the first connecting portion. Further, thearea of sides facing each other of the respective first connectingportion and the second connecting portion may be formed different.

Further, in a method of manufacturing a thin film magnetic head of theinvention, the width of the first magnetic pole along a surface which isfacing the recording medium may be formed to be wider than that of thesecond magnetic pole.

Further, in a method of manufacturing a thin film magnetic head of theinvention, the whole part of a film-thickness direction of the thin filmcoil may be formed in a region where the first insulating layer isformed.

Further, in a method of manufacturing a thin film magnetic head of theinvention, after flattening the second insulating layer, a write gaplayer may be formed on the second insulating layer; after forming thesecond magnetic pole on the write gap layer, a third insulating layermay be formed at least on the write gap layer; then, at least one layerof thin film coil may be formed on the third insulating layer on thewrite gap layer; and the thin film coil is covered with other insulatinglayer which is different from the first to third insulating layers.

Further, in a method of manufacturing a thin film magnetic head of theinvention, after forming the other insulating layer with inorganicmaterials, the other insulating layer may be flattened so that itssurface forms the same surface with the surface of the second magneticpole and, then, the second magnetic layer may be formed on the secondmagnetic pole and the other insulating layer being flattened or afterselectively forming the other insulating layer with organic materials,the second magnetic layer may be formed on the second magnetic pole andthe other insulating layer.

Further, in a method of manufacturing a thin film magnetic head of theinvention, a surface of the second magnetic layer which is anopposite-side of a facing surface of the write gap layer may be formedto be flat. Further, the thin film coil may be buried in a region wherethe insulating layers are formed, and a surface of the second magneticlayer, which is in an opposite-side of a facing surface of the write gaplayer may be flattened.

Further, a method of manufacturing a thin film head of the invention mayinclude a step of forming a magneto resistive element for reading out.

Other objects, characteristics and effects of the invention will be madeevident in the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are cross sections for describing a manufacturingprocedure of a thin film magnetic head according to a first embodimentof the invention.

FIGS. 2A and 2B are cross sections for describing the procedurefollowing FIGS. 1A and 1B.

FIGS. 3A and 3B are cross sections for describing the procedurefollowing FIGS. 2A and 2B.

FIGS. 4A and 4B are cross sections for describing the procedurefollowing FIGS. 3A and 3B.

FIGS. 5A and 5B are cross sections for describing the procedurefollowing FIGS. 4A and 4B.

FIGS. 6A and 6B are cross sections for describing the procedurefollowing FIGS. 5A and 5B.

FIGS. 7A and 7B are cross sections for describing the procedurefollowing FIGS. 6A and 6B.

FIGS. 8A and 8B are cross sections for describing the procedurefollowing FIGS. 7A and 7B.

FIG. 9 is a plan view of a thin film magnetic head manufactured throughthe first embodiment of the invention.

FIGS. 10A and 10B are cross sections for describing the constitution ofa thin film magnetic head according to the first embodiment of theinvention.

FIG. 11 is a plan view of a thin film magnetic head manufactured througha second embodiment of the invention.

FIGS. 12A and 12B are cross sections for describing the constitution ofa thin film magnetic head according to a third embodiment of theinvention.

FIGS. 13A and 13B are cross sections for describing the constitution ofa thin film magnetic head according to a fourth embodiment of theinvention.

FIGS. 14A and 14B are cross sections for describing the constitution ofa thin film magnetic head according to a fifth embodiment of theinvention.

FIGS. 15A and 15B are cross sections for describing the constitution ofa thin film magnetic head according to a fifth embodiment of theinvention.

FIGS. 16A and 16B are cross sections for describing the constitution ofa thin film magnetic head according to a sixth embodiment of theinvention.

FIGS. 17A and 17B are cross sections for describing the constitution ofa thin film magnetic head according to a seventh embodiment of theinvention.

FIGS. 18A and 18B are cross sections for describing the constitution ofa thin film magnetic head according to a eighth embodiment of theinvention.

FIGS. 19A and 19B are cross sections for describing the manufacturingprocedure of a thin film magnetic head according to a ninth embodimentof the invention.

FIGS. 20A and 20B are cross sections for describing the procedurefollowing FIGS. 19A and 19B.

FIGS. 21A and 21B are cross sections for describing the procedurefollowing FIGS. 20A and 20B.

FIGS. 22A and 22B are cross sections for describing the procedurefollowing FIGS. 21A and 21B.

FIGS. 23A and 23B are cross sections for describing the procedurefollowing FIGS. 22A and 21B.

FIGS. 24A and 24B are cross sections for describing the procedurefollowing FIGS. 23A and 23B.

FIGS. 25A and 25B are cross sections for describing the procedurefollowing FIGS. 24A and 24B.

FIG. 26 is a plan view of a thin film magnetic head manufactured throughthe ninth embodiment of the invention.

FIGS. 27A and 27B are a cross section for describing the constitution ofa thin film magnetic head according to a tenth embodiment of theinvention.

FIGS. 28A, 28B and 28C are a cross section for describing theconstitution of a thin film magnetic head according to a eleventhembodiment of the invention.

FIG. 29 is a cross section for describing a modification example of athin film magnetic head according to the first embodiment of theinvention.

FIG. 30 is also a cross section for describing a modification example ofa thin film magnetic head according to the first embodiment of theinvention.

FIGS. 31A and 31B are cross sections for describing a manufacturingprocedure of a thin film magnetic head according to the invention.

FIGS. 32A and 32B are cross sections for describing the procedurefollowing FIGS. 31A and 31B.

FIGS. 33A and 33B are cross sections for describing the procedurefollowing FIGS. 32A and 32B.

FIGS. 34A and 34B are cross sections for describing the procedurefollowing FIGS. 33A and 33B.

FIGS. 35A and 35B are cross sections for describing the procedurefollowing FIGS. 34A and 34B.

FIGS. 36A and 36B are cross sections for describing the procedurefollowing FIGS. 35A and 35B.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the invention will be described with reference to thedrawings in the followings.

[First Embodiment]

FIGS. 1A and 1B to FIGS. 8A and 8B illustrate a manufacturing procedureof a composite thin film magnetic head as a thin film magnetic headaccording to the first embodiment of the invention respectively. FIGS.1A˜8A show cross sections vertical to the track surface (ABS), and FIGS.1B˜8B show cross sections parallel to the track surface of the magneticpole portion.

First, the constitution of a composite thin film magnetic head accordingto the embodiment of the invention will be described with reference toFIGS. 8A and 8B. The magnetic head comprises a magnetoresistive readinghead (called reproduction head portion in the followings) 1A forreproduction and a inductive recording head (called recording headportion in the followings) 1B for recording.

The reproduction head portion 1A is a pattern of magnetoresistive film(called GMR film in the followings) 15 being formed on a substrate 11made of, for example, aluminum oxide and titanium carbide (AL₂O₃ TiC)through an insulating layer 12 formed with, for example, alumina(aluminum oxide, Al₂O₃), a bottom shield layer 13 formed with, forexample, permalloy (NiFe), and a shield gap layer 14 formed with, forexample, alumina in order. Further, a lead terminal layer 15 a made ofmaterial such as tantalum (Ta) or tungsten (W) which does not diffuseonto the GMR films is formed on the shield gap layer 14, and the leadterminal layer 15 a is electrically connected to a GMR film 15. The GMRfilm 15 is formed with a free layer made of, for example, permalloy(NiFe alloy) or with several types of materials having magnetoresistive,such as anti-ferromagnetic film made of PtMn, IrMn, and RuRhMn. A shieldgap layer 17 made of such as alumina is stacked on the GMR film 15 andthe lead terminal layer 15 a. In other words, the GMR film 15 and thelead terminal layer 15 a are buried between the shield gap layers 14 and17. Further, it is not specifically limited to the GMR film 15 but alsoother magnetoresistive film such as the AMR film can be used in theinvention.

The recording head portion 1B is a top pole formed on the reproductionhead portion 1A through the upper shield layer-cum-bottom pole for theGMR film 15 and a write gap layer 22.

In the embodiment, the bottom pole is formed being divided into a bottompole layer (bottom pole) 18 formed on the shield gap layer 17, and abottom pole tip 19 a formed on the bottom pole layer 18 on the tracksurface side. Likewise, the top pole is divided into two:one is the toppole tip 23 a formed on a write gap layer 22 on the bottom pole tip 19 aon the track surface side, and the other is a yoke-cum-top pole layer(top pole) 25 which has a contact with the top pole tip 23 a, and isformed along the upper surface of the apex including the coil which isto be described later. The top pole layer 25 is magnetically coupled tothe bottom pole layer 18 through the top connecting portion 23 b and thebottom connecting portion 19 b in the position which is the opposite(right-hand side in FIG. 8A) of the track surface.

The bottom pole layer 18, the bottom pole tip 19 a, the bottomconnecting portion 19 b, the top pole tip 23 a, the top connectingportion 23 b and the top pole layer 25 are formed with, for example,high saturation flux density material (Hi-Bs material), for example,NiFe (Ni: 50 weight percentage, Fe: 50 weight percentage), NiFe (Ni: 80weight percentage, Fe: 20 weight percentage), FeN, FeZrNP, CoFeN and soon respectively.

In the recording head portion 1B, the bottom pole tip 19 b facing thetop pole tip 23 a has a trim structure in which part of the surface areais processed to a convex shape. As a result, when writing data, wideningof the effective write track width, that is, widening of the magneticflux in the bottom pole can be suppressed.

In the embodiment, the bottom pole layer 18 corresponds to the firstmagnetic layer of the invention, and the bottom pole tip 19 a to thefirst magnetic pole of the invention respectively. Further, the top poletip 23 a corresponds to the second magnetic pole of the invention, andthe top pole layer 25 to the second magnetic layer of the inventionrespectively.

In the embodiment, a first layer of the thin film coil 21 is formed in aconcave region between bottom pole tip 19 a and the bottom connectingportion 19 b on the bottom pole layer 18. That is, an insulating layer20 a is formed in inner wall surface (bottom and side-wall surface) ofthe concave region, and a thin film coil 21 is formed on the insulatinglayer 20 a. Between the bundles of coils of the thin film coil 21 isburied with an insulating layer 20 b, and the surface of the insulatinglayer 20 b and the bottom pole tip 19 a are flattened so that bothsurface make the same surface. For this, a step of the apex areaincluding a thin film coil 24 which is to be described later is loweredabout the size of the thin film coil 21. The insulating layer 20 acorresponds to the first insulating layer of the invention, and theinsulating layer 20 b to the second insulating layer of the inventionrespectively.

A write gap layer 22 is extended on the flattened insulating layer 20 band the thin film coil 21. An insulating layer 20 c is formed in theconcave region between the top pole tip 23 a and the top connectingportion 23 b on the write gap layer 22. A second layer of the thin filmcoil 24 is formed on the insulating layer 20 c. The thin film coil 24 iscovered with an insulating layer 20 d made of, for example, alumina. Theinsulating layer 20 c corresponds to a third insulating layer of theinvention and the insulating layer 20 d corresponds to other insulatinglayer of the invention respectively.

A yoke-cum-top pole layer 25 is formed on the insulating layer 20 d. Thetop pole layer 25 is covered with an over coat layer 26. The thin filmcoils 21 and 24 are electrically connected to each other on the bordersurface between the insulating layer 20 b and the insulating layer 20 d,though not shown in the figure.

With the magnetic head, information is read out from a magnetic disk,not shown in the figure, by using megnetoresistive effect of the GMRfilm 15 in the reproduction head portion 1A, while information iswritten to a magnetic disk by using a change of magnetic flux betweenthe top pole tip 23 a and the bottom pole tip 19 a by the thin filmcoils 21 and 24 in the recording head portion 1B.

Next, a manufacturing method of the composite thin film magnetic head isto be described.

In the manufacturing method according to the embodiment of theinvention, first, as shown in FIGS. 1A and 1B, an insulating layer 12 ofabout 3˜5 μm in thickness, made of, for example, alumina (Al₂O₃) isformed on a substrate 11 made of, for example, aluminum oxide andtitanium carbide (Al₂O₃.TiC) by, for example, sputtering method. Next, abottom shield layer 13 for a reproduction head is formed by selectivelyforming permalloy (NiFe) of about 3 μm in thickness on the insulatinglayer 12 by plating method using a photoresist film as a mask. Then, analumina film (not shown in the figure) of about 4˜6 μm is formed by, forexample, sputtering or CVD (Chemical Vapor Deposition) method and isflattened by CMP.

Next, as shown in FIGS. 2A and 2B, a shield gap layer 14 is formed bydepositing, for example, alumina of about 100˜200 nm in thickness on thebottom shield layer 13 by sputtering method. Then, an MR film 15 forforming such as an MR element for reproduction is formed in tens ofnanometers in thickness on the shield gap layer 14, and a desired shapeis obtained by photolithography with high precision. Next, a leadterminal layer 15 a facing the GMR film 15 is formed by lift-off method.Next, a shield gap layer 17 is formed on the shield gap layer 14 and thelead terminal layer 15 a, and the GMR film 15 and the lead terminallayer 15 a are buried in the shield gap layers 14 and 17.

Next, a top shield-cum-bottom pole layer (bottom pole) 18 of about1.0˜1.5 μm in thickness, made of, for example, permalloy (NiFe) isformed on the shield gap film 17.

Next, as shown in FIGS. 3A and 3B, the bottom pole tip 19 a and thebottom connecting portion 19 b of about 2.0˜2.5 μm in thickness areformed on the bottom pole layer 18. Here, the bottom pole tip 19 a isformed with the track side tip portion being in the vicinity of the GMR(MR) height 0 position, and with the opposite side of the track surfacebeing in the throat height 0 position. The bottom pole tip 19 a and thebottom connecting portion 19 b may be formed with plating films such asNiFe as described, and may also be formed with sputter films such asFeN, FeZrNP and CoFeN.

Further, the insulating layer 20 a of about 0.3˜0.6 μm in thickness,made of insulating materials such as alumina is formed all over thesurface by, for example, sputtering method or CVD method.

Next, as shown in FIGS. 4A and 4B, a first layer of the thin film coil21 for a inductive-type recording head, made of, for example, copper(Cu) is formed in thickness of about 1.5˜2.5 μm in the concave regionformed between the bottom pole tip 19 a and the bottom connectingportion 19 b by, for example, electroplating method.

Next, as shown in FIGS. 5A and 5B, after forming the insulating layer 20b of about 3.0˜4.0 μM in thickness, made of an insulating material suchas alumina all over the surface by sputtering method, the surface isflattened by, for example, CMP method so as to make the surface of thebottom pole tip 19 a be exposed. Here, in the embodiment, the surface ofthe thin film coil 21 is exposed at the same time, however, part of thesurface, except for the connecting portion of the thin film coil 21 anda second layer of the thin film coil 24 which is to be described lateris not required to be exposed.

Next, as shown in FIGS. 6A and 6B, a write gap layer 22 of about 0.2˜0.3μm in thickness, made of an insulating material such as alumina isformed by sputtering method. The write gap layer 22 may be formed withaluminum nitride (AlN), silicon oxide, silicon nitride and so on,besides with alumina. Then, an opening 22 a for connecting the top poleand the bottom pole is formed by patterning the write gap layer 22 byphotolithography.

Further, the top pole tip 23 a for determining the track width of therecording head is formed on the write gap layer 22 by photolithography.That is, a magnetic layer of about 2.5˜3.5 μm in thickness, made of highsaturation flux density material (Hi-Bs material), for example, NiFe(Ni: 50 weight percentage, Fe: 50 weight percentage), NiFe (Ni: 80weight percentage, Fe: 20 weight percentage), FeN, FeZrNP, CoFeN and soon is formed on the write gap layer 22 by, for example, sputteringmethod. Further, the top pole tip 23 a is formed by selectively removingthe magnetic layer by, for example, ion-milling with Ar (argon) using aphotoresist mask, while the top connecting portion 23 b for magneticallyconnecting the top pole and the bottom pole is formed. The top pole tip23 a and the top connecting portion 23 b may be etched using a mask madeof inorganic insulating layer such as alumina, instead of using thephotoresist mask. Further, it may be formed by, other than thephotolithography, plating method or sputtering method.

Further, having the top pole tip 23 a as a mask, the write gap layer 22and the bottom pole tip 19 a in the vicinity are etched in aself-aligned manner. That is, a recording track with a trim structure isformed by further etching the bottom pole tip 19 a about 0.3˜0.6 μm byion-milling with Ar after selectively removing the write gap layer 22 byRIE (Reactive Ion Etching) with chlorine gas (Cl₂, CF₄, BCl₂, SF₆ and soon), having the top pole tip 23 a as a mask.

Further, the insulating layer 20 c of about 0.3˜0.6 μm in thickness,made of, for example, alumina is formed all over the surface by, forexample, sputtering method or CVD method. Further, a second layer of thethin film coil 24 for an inductive-type recording head, made of, forexample, copper (Cu) is formed on the insulating layer 20 c in thicknessof about 1.5˜2.5 μm by, for example, electroplating.

Next, as shown in FIGS. 7A and 7B, the insulating layer 20 d of about3˜4 μm in thickness, made of such as alumina is formed all over thesurface by, for example, sputtering method or CVD method. The insulatinglayer 20 d and the insulating layer 20 c may be formed with otherinsulating materials such as silicon dioxide (SiO₂) or silicon nitride(SiN) besides with alumina. Then, the insulating layer 20 d and theinsulating layer 20 c are etched so as to make the surfaces of the toppole tip 23 a and the top connecting portion 23 b be exposed, and areflattened so that the surfaces of the insulating layers 20 c and 20 d,and each surface of the top pole tip 23 a and the top connecting portion23 b forms the same surface.

Next, as shown in FIGS. 8A and 8B, the top pole layer 25 of about 3˜4 μmin thickness is formed using the same material as, for example, the toppole tip 23 a by, for example, electroplating method or sputteringmethod. The top pole layer 25 has a contact with the bottom connectingportion 19 b through the top connecting portion 23 a in a position rearof the thin film coils 21 and 24 from the track surface side (right-handside in FIG. 8A), and is magnetically coupled to the bottom pole layer18. At last, an over coat layer 26 of about 30 μm in thickness, made ofalumina is formed on the top pole layer 25 by, for example, sputteringmethod. A thin film magnetic head is completed by performing a slidermachine processing and by forming a track surface (ABS) of a recordinghead and a reproducing head.

FIG. 9 is a plan view of a thin film magnetic head according to theembodiment of the invention. The figure shows a state before the slidermachine processing is performed. In these figures, TH represents thethroat height, and the throat height is determined by the top pole sideof the edge frame of the insulating layer 20 a, that is, by the oppositeside edge frame of the track surface of the bottom pole tip 19 a.Further, 21 a represents a lead wire of the thin film coil 21.

With the embodiment described above, effects described in the followingscan be obtained.

(1) In the embodiment, the bottom pole is divided into the bottom poletip 19 a and the bottom pole layer 18, and the bottom pole tip 19 a isformed on a flat surface of the bottom pole layer 18. As a result, theinsulating layers 20 a and 20 b made of inorganic materials can beburied in the concave region between the bottom pole tip 19 a and thebottom connecting portion 19 b. Accordingly, the throat height isdetermined by the edge frame of the bottom pole tip 19 a side of theinsulating layer 20 a (that is, edge frame of the opposite side of thetrack surface of the bottom pole tip 19 a). As a result, precise controlof the throat height can be achieved since a pattern shift of the edgeframe by heat annealing or profile deterioration does not occur, unlikethe photoresist film of a related art. Further, precise control of theGMR height and apex angle can be achieved.

(2) Further, in the embodiment, as shown in FIGS. 11A and 11B, when eachpattern is seen from right above, the width of the bottom pole tip 19 ais made wider than the width of the top pole tip 23 a. As a result, evenif the top pole tip 23 a is a narrow track with half-micron width, themagnetic flux does not saturate in the vicinity of the bottom pole tip19 a.

(3) Further, in the embodiment, the insulating films 20 a and 20 b madeof inorganic materials are provided between the thin film coil 21 andthe top shield-cum-bottom pole layer 18, and the write gap film 22 andthe insulating layer 20 c are provided between the thin film coils 21and 24. As a result, by adjusting the thickness of each insulatinglayer, a large insulating pressure resistant between each of the thinfilm coils 21 and 24, and the top shield can be obtained so thatinsulating character can be maintained and leaking of the magnetic fluxfrom the thin film coils 21 and 24 can be decreased.

(4) Further, in the embodiment, the top pole is divided into the toppole tip 23 a and the top pole layer 25, and the top pole tip 23 a isformed on a flat surface of the bottom pole tip 19 a. As a result, thetop pole tip 23 a for determining the recording track width can beformed to a submicron measurement with high precision. In addition, inthe embodiment, a first layer of the thin film coil 21 is buried in theconcave region adjacent to the bottom pole tip 19 a by the insulatinglayer 20 b, while the surface of the insulating layer 20 b is flattenedso that its surface forms the same surface with the surface of thebottom pole tip 19 a. That is, the step of the apex area including asecond layer of the thin film coil 24 becomes lower about the size ofthe first layer of the thin film coil 21 comparing to the structure of arelated art. Accordingly, when forming the top pole layer 25 which has acontact partially with the top pole tip 23 a by photolithography,differences in thickness of the photoresist film in the top and thebottom of the apex area is decreased. As a result, micronization of thesubmicron measurement of the top pole layer 25 can be achieved.Accordingly, with the thin film magnetic head obtained through theembodiment, high surface density recording by a recording head can beachieved, and performance of the recording head can be improved bystacking the coils to two layers and three layers. When applyingphotolithography to the top pole tip 23 a and the top pole layer 25, byusing an inorganic insulating layer as a mask instead of thephotoresist, micronization of the top pole tip 23 a and the top polelayer 25 with higher precision can be achieved. Further, even in a casewhere the top pole tip 23 a and the top pole layer 25 are formed by suchas sputtering, other than photolithography, micronization of the toppole tip 23 a and the top pole layer 25 can be achieved since influenceof the steps of the apex area is decreased as well.

Further, in the embodiment, since there is no slope area of thephotoresist pattern, unlike that of a related art, the first and thesecond layer of the thin film coils 21 and 24 can be formed on a flatarea so that the distance between the coil outer peripheral edge by theslope and the throat height 0 position does not prevent the yoke lengthfrom shortening. Accordingly, in the embodiment, the yoke length can bemade shorter, and high frequency characteristic of the recording headcan be improved prominently. In the embodiment, it can be designed witha locating error by photolithography of equal to, or less than 0.1μm˜0.2 μm, so that the yoke length can be decreased to equal to or lessthan 50% of that of a related art.

(6) Further, in the embodiment, the magnetic layers such as the top poletip 23 a and the top pole layer 25 are formed with high saturation fluxdensity (Hi-Bs) materials, so that, even if the track width becomesnarrower, the magnetic flux generated in the thin film coils 21 and 24does not saturate on the way, but effectively reach the top pole tip 23a and the bottom pole tip 19 a. As a result, a recording head without amagnetic loss can be achieved.

(7) Further, in the embodiment, the top pole layer 25 formed on the toppole tip 23 a for determining the track width is not exposed to thetrack surface, so that side write by the top pole layer 25 does notoccur.

Other embodiment of the invention will be described in the followings.In the description, like numerals are adopted to the structuresidentical to the first embodiment and the description is omitted. Thedistinguished structures will be described in the followings.

[Second Embodiment]

FIGS. 10A and 10B show the constitution of a composite thin filmmagnetic head according to a second embodiment of the invention. In thefirst embodiment, the top pole layer 25 is formed in a position recessedfrom the track surface, however, in this embodiment, the top pole layer25′ along with the top pole tip 19 a are exposed to the track surface.Here, by having the thickness of the top pole tip 23 a, for example, 2˜3μm, side write can be avoided without having a structure in which thetop pole layer is recessed from the track surface (recessed structure).Other operation effects are identical to the first embodiment. FIGS. 11Aand 11B show a plan view of a thin film magnetic head according to theembodiment.

In the embodiment, as shown in FIGS. 12A and 12B, the procedure untilforming the second layer of the thin film coil 24 is identical to thefirst embodiment. After that, the thin film coil 24 is covered with aphotoresist film 30, then, the top pole layer 25 is formed on thephotoresist film 30 without the pole tip being exposed to the tracksurface. In the embodiment, unlike the first embodiment, flattening thesurface by CMP after forming the second layer of the thin film coil 24is not performed. Accordingly, manufacturing cost is decreased comparingto the first embodiment. The second layer of the thin film coil 24 withfive turns is formed in a flat area of the first layer of the thin filmcoil 21 with six turns, so that the distance from the outer peripheralend of the thin film coil 24 to the throat height 0 position does notaffect the yoke length. Other operation effects are identical to thoseof the first embodiment.

[Fourth Embodiment]

FIGS. 13A and 13B show a fourth embodiment of the invention. In theembodiment, the structure of the top pole is not divided into two. Inother words, a second layer of the thin film coil 24 is formed on thewrite gap layer 22 without forming the top pole tip, then, the thin filmcoil 24 is covered with the photoresist film 30. Then, the top polelayer 25′ is formed on the photoresist film 30 with the pole tip (poleportion) being exposed to the track surface. In the embodiment, unlikethe first embodiment, flattening the surface by CMP after forming thesecond layer of the thin film coil 24 is not performed, so that themanufacturing cost is decreased comparing to the first embodiment. Otheroperation effects are identical to those of the first embodiment.

[Fifth Embodiment]

FIGS. 14A and 14B show a composite thin film magnetic head according toa fifth embodiment of the invention. In the magnetic head, the coilportion is the thin film coil 21 with a single layered structure, andthe thin film coil 21 is formed with narrower pitch than the embodimentsdescribed above. Further, an insulating layer 20 e of, for example, 1.0μm in thickness, made of photoresist is formed on the thin film coil 21and the write gap layer 22 is formed, then, the top pole layer 25″ isformed to be exposed to the track surface without forming the top poletip. In the embodiment, the top pole layer 25″ can be formed directly onthe flattened surface so that micronization of the track width of therecording head can be achieved further than the embodiments describedabove.

As shown in FIGS. 15A and 15B, without forming the insulating layer 20 e(FIG. 14A), the same effect as described above can be obtained also in acase where the write gap layer 22 is formed on the bottom pole tip 19 aand the thin film coil 21, and the top pole layer 25″ is formed, then,the surface of the top pole layer 25″ is flattened by, for example, CMPmethod.

[Sixth Embodiment]

FIGS. 16A and 16B show a sixth embodiment of the invention. Theembodiment has a structure in which the whole part of a first layer ofcoil forming portion is buried by the insulating layer 20 b made of, forexample, alumina in the first embodiment (FIGS. 8A and 8B). Thedescription will be omitted since the effects of the embodiment aresubstantially identical to those of the first embodiment.

[Seventh Embodiment]

FIGS. 17A and 17B show a seventh embodiment of the invention. Theembodiment has a structure in which the whole part of the first layer ofcoil forming portion is buried by the insulating layer 20 b made of, forexample, alumina in the second embodiment (FIGS. 10A and 10B). Thedescription is to be omitted since the effects of the embodiment aresubstantially identical to those of the second embodiment.

[Eighth Embodiment]

FIGS. 18A and 18B show an eighth embodiment of the invention. Theembodiment has a structure in which the whole part of the first layer ofcoil forming portion is buried by the insulating layer 20 b made of, forexample, alumina in the third embodiment (FIGS. 12A and 12B), and thetwo layers of the thin film coils 24 and 24 a are covered with thephotoresist film 30. The description is to be omitted since the effectsof the embodiment are substantially identical to those of the thirdembodiment.

FIGS. 19A and 19B to FIGS. 25A and 25B show the manufacturing procedureof a thin film magnetic head according to a ninth embodiment of theinvention.

In the embodiment, as shown in FIGS. 25A and 25B, the top pole tip 23 ais formed longer than the bottom pole tip 19 a. Further, the width ofthe top connecting portion 23 b is different from the width of thebottom connecting portion 19 b, that is, the areas of the two aredifferent. Specifically, the area of the top connecting portion 23 b islarger than the area of the bottom connecting portion 19 b. Further, thebottom connecting portion 19 b has a contact with the center position ofthe top connecting portion 23 b. As a result, flow of the magnetic fluxfrom the top pole layer 25 to the bottom pole layer 18 becomes smooth.

The manufacturing method of the thin film magnetic head is substantiallyidentical to the first embodiment except that the top pole tip 23 a isformed longer than the bottom pole tip 19 a from the track surface toinside, the top connecting portion 23 b is formed wider than the bottomconnecting portion 19 b, and the bottom connecting portion 19 b has acontact with the center position of the top connecting portion 23 b.Accordingly, description in detail is to be omitted.

FIG. 26 is a plan view of a thin film magnetic head according to theembodiment. This figure shows a state before the slider machineprocessing is performed. In the figure, TH represents the throat height,and the throat height TH is determined by the pole tip side edge frameof the insulating layer 20 a, that is, the opposite side frame edge ofthe track surface of the bottom pole tip 19 a. In the figure, TH is GMRheight since the throat height TH is met with the GMR height. One of theedge of the lead terminal 21 a is connected to the thin film coil 21.The other edge of the lead terminal 21 a is connected to an electrodeextract pad (not shown in the figure). Further, the other edge of thelead terminal layer 15 a whose other edge is connected to the MR element15 is also connected to the electrode extract pad (not shown in thefigure).

In the embodiment, in addition to the effects of the first embodiment,the effects which will be described in the followings can be furtherobtained.

(1) In the embodiment, since the top pole tip 23 a is formed to belonger than the bottom pole tip 19 a, the contact area of the top poletip 23 a and the top pole layer 25 can be made larger than a case wherethe top pole tip 23 a and the bottom pole tip 19 a are formed to be thesame length, and so that magnetic coupling can be better achieved inthat area. Especially, this structure is effective when the top polelayer 25 is provided in a recessed position from the track surface(recessed structure), like the embodiment. In other words, if the toppole layer 25 is formed in a position which is closer to the tracksurface than the throat height=0 position (opposite edge frame of thetrack surface of the bottom pole tip 19 a), for example, the vicinity ofTH=0.5 μm, side write, which is writing information to adjacent track bythe top pole layer 25, occurs. Idealistically, the top pole layer 25 isbetter to be formed in a position further from the track surface than TH0 position. On the other hand, in the embodiment, the bottom pole tip 19a for determining TH is magnetically coupled to the top pole layer 25through the top pole tip 23 a. The top pole tip 23 a and the top polelayer 25 are required to be firmly connected in the opposite directionof the track surface from the TH 0 position. Accordingly, it ispreferable to form the top pole tip 23 a longer than the bottom pole tip19 a.

(2) By the way, the top pole tip 23 a and the bottom pole tip 19 a aremicronized and as the width becomes narrower, the contact area of thetop pole and the bottom pole, that is, the width of the bottomconnecting portion 19 b and the top connecting portion 23 b becomenarrower. When the width of the bottom connecting portion 19 b and thetop connecting portion 23 b are micronized as described, and when theangle between the sidewall of the bottom connecting portion 19 b and thebottom magnetic layer 18, or the angle between the sidewall of the topconnecting portion 23 b and the top magnetic layer 25 are verticalrespectively, there is a problem that the magnetic flux may saturate inthat area. However, in the embodiment, the area of the top connectingportion 23 b is larger than that of the bottom connecting portion 19 band further, the bottom connecting portion 19 b is facing the centerarea of the top connecting portion 23 b so that, when looking at it incross section, the whole contact area takes a shape having a slope alongthe slope surface between the top and bottom coils, that is, the wholecontact area takes a shape as if it is a funnel. As a result, flow ofthe magnetic flux from the top pole to the bottom pole becomes smoothand magnetic coupling of both poles can be better achieved. Taper anglemay be provided in each of the top connecting portion 23 b and thebottom connecting portion 19 b, and with the structure like this, flowof the magnetic flux from the top pole to the bottom pole becomessmoother. Further, inversely, the area of the bottom connecting portion19 b may be formed larger than the area of the top connecting portion 23b.

(3) Further, in the embodiment, as shown in FIGS. 25A and 25B, the toppole tip 23 a which determines the track width is thinner than the toppole layer 25. As a result, even if much magnetic flux flows from thetop pole layer 25, the magnetic flux does not saturate in that areasince the distance between the top pole layer 25 and the write gap layer22 is short. Accordingly, an over write characteristic and a nonlineartransition (NLTS) is improved.

[Tenth Embodiment]

FIGS. 27A and 27B show the constitution of a composite thin filmmagnetic head according to a tenth embodiment of the invention. In theninth embodiment, a second layer of the thin film coil 24 is totallyburied under the surface of the top pole tip 23 a, that is, completelyinside the flattened insulating layer 20 d, however, when the top poletip 23 a is thin, the surface of the thin film coil 24 may be exposedduring the flattening procedure of such as CMP. In the embodiment, tomaintain insulating characteristic between the thin film coil 24 and thetop pole layer 25 in such a case, an insulating layer 30 of about, forexample, 1.0 μm in thickness, made of photoresist is selectively formedbetween the thin film coil 24 and the top pole layer 25. Otherstructures and operation effects are identical to those of the firstembodiment so that the description is to be omitted.

[Eleventh Embodiment]

In the embodiment, as shown in FIGS. 28A˜28C, the procedure untilforming the second layer of the thin film coil 24 is identical to theninth embodiment. After that, the thin film coil 24 is covered with aphotoresist film 31, then, the top pole layer 25 is formed on thephotoresist film 31 without having the top tip exposed to the tracksurface. FIG. 28C is a plan view of the bottom pole tip 19 a, the bottomconnecting portion 19 b, the top pole tip 23 a, the top connectingportion 23 b and the top pole layer 25 taken out from FIGS. 28A and 28B.

In the embodiment, unlike the ninth embodiment, flattening by CMP is notrequired to be performed after the second layer of the thin film coil 24is formed. Accordingly, the manufacturing cost is decreased comparing tothe ninth embodiment. The second layer of the thin film coil 24 withfive turns is formed in a flat area of the first layer of the thin filmcoil 21 with six turns, so that the distance from the outer peripheralend of the thin film coil 24 to the throat height 0 position does notaffect the yoke length. Other structures and operation effects areidentical to those of the ninth embodiment so that the description is tobe omitted.

The plan shape of the top pole tip 23 a and the top pole layer 25 arenot limited to the those shown in FIG. 28C, but may take a shape shownin, for example, FIG. 29.

The invention also includes other various modifications, not limiting tothe embodiments. For example, in the embodiments, examples of formingthe top pole tip 23 a and the top pole layer 25 and so on with NiFe (Ni:50 weight percentage, Fe: 50 weight percentage), NiFe (Ni: 80 weightpercentage, Fe: 20 weight percentage), and high saturation flux densitymaterials such as FeN, FeCoZr and so on are described, however, astructure of stacking more than two kinds of the materials may bepossible.

Further, in the embodiments described above, the thin film coil to beburied in the concave formed adjacent to the bottom pole tip 19 a is asingle layer, however, it may be a stacking structure in which two ormore layers of coils are buried.

Further, in the embodiments described above, the bottom pole tip 19 a isformed to take a shape in which the sidewall is vertical to the bottompole layer 18, however, as shown in FIG. 30, a slope surface (taper) 31of about, for example, θ=50˜70°, according to the thickness of the coil,may be provided in the sidewall. By having such a structure, saturationof the magnetic flux in the connecting portion of the bottom pole layer18 and the bottom pole tip 19 a is suppressed and flow of the magneticflux becomes smooth.

In addition, in the embodiments described above, a case where theinsulating layer 20 b and the insulating layer 20 d are formed withalumina, silicon dioxide or silicon nitride is described, however, aftercovering the thin film coil with, for example, alumina, the concave areaof the surface may be buried with SOG (Spin On Glass) film and may beflattened.

Further, in the embodiments described above, the first layer of the thinfilm coil is buried by the insulating layer in the concave regionadjacent to the bottom pole tip 19 a, however, the whole concave regionmay be the inorganic-type insulating layer made of, for example,alumina. In the embodiments described above, a structure in which thebottom pole is made to correspond to the first magnetic layer and thetop pole is made to correspond to the second magnetic layer respectivelyis shown, however, a structure in which, each corresponds to the otherway around may also be possible. That is, a structure in which thebottom pole corresponds to the second magnetic layer and the top polecorresponds to the first magnetic layer respectively may be possible.

Further, in each embodiment described above, a manufacturing method of acomposite thin film magnetic head is described. The invention may beapplied to manufacturing of a thin film magnetic head for recordingonly, having an inductive-type transducer element for writing or of athin film magnetic head for recording/reproducing. Further, theinvention may be applied to manufacturing of a thin film magnetic headwith a structure in which the order of stacking the recording elementand reproducing element is reversed.

As described, according to the thin film head, or the manufacturingmethod of a thin film magnetic head of the invention, the first magneticpole is formed to be divided from the first magnetic layer and to beconvex shape on the first magnetic layer so that the insulating layermade of an inorganic material can be buried in the concave adjacent tothe first magnetic pole. As a result, the throat height is determined bythe opposite side edge frame of the track surface of the first magneticpole, so that a pattern shift of the edge frame or deterioration ofprofile does not occur, unlike the photoresist film of a related art andprecise control of the throat height can be achieved.

Further, by burying the thin film coil in the concave adjacent to thefirst magnetic pole, a step of the apex area can be lowered comparing tothe structure of a related art. After that, in the procedure forming thesecond magnetic layer by photolithography, difference in the thicknessof the photoresist film in the top and bottom of the apex area isdecreased and so that micronization of the submicron measurement of thesecond magnetic layer can be achieved. As a result, high surface densityrecording by a recording head becomes possible, and performance of therecording head can be improved by stacking the coil to two layers orthree layers.

Further, the second magnetic pole facing the first magnetic pole, isdivided from the second magnetic layer and the second magnetic pole isformed longer than the first magnetic pole from the track surface toinside. As a result, the second magnetic pole can be micronized to thesubmicron measurement, while the contact area of the second magneticpole and the second magnetic pole is increased, flow of the magneticflux becomes smooth, precise control of the throat height can beachieved, and a thin film magnetic head with high precision can beachieved.

With the description made above, it is evident that various embodimentsor modifications of the invention can be achieved. Accordingly, withinthe scope of the appended claims, the invention may be practicedotherwise than as specifically described.

What is claimed is:
 1. A method of manufacturing a thin film magnetichead including a first magnetic pole and a second magnetic pole that aremagnetically coupled to each other and face each other with a gap layerin between, in a recording-medium-facing surface and a thin film coilfor generating magnetic flux, the method comprising the steps of:forming a first magnetic layer and then forming the first magnetic poleon the first magnetic layer so as to be magnetically coupled to part ofthe first magnetic layer; forming a first insulating layer with aninorganic material extendedly from a surface of the first magnetic poleopposite to the recording-medium-facing surface to a top surface of thefirst magnetic layer; forming the gap layer on the first magnetic poleand then forming on the gap layer the second magnetic pole longer thanthe first magnetic pole, and forming a second magnetic layer so as to bemagnetically coupled to part of the second magnetic pole.
 2. The methodof manufacturing a thin film magnetic head according to claim 1, whereina first thin film coil is formed on the first insulating layer and thenthe first thin coil is buried with a second insulating layer.
 3. Themethod of manufacturing a thin film magnetic head according to claim 2,wherein a top surface of the second insulating layer is planarized to besubstantially leveled with a top surface of the first magnetic pole. 4.The method of manufacturing a thin film magnetic head according to claim3, wherein the gap layer is formed further extendedly along theplanarized second insulating layer, a third insulating layer is formedon the gap layer, and a second thin film coil is formed on the thirdinsulating layer.
 5. The method of manufacturing a thin film magnetichead according to claim 4, wherein the second thin film coil is buriedwith a fourth insulating layer, a top surface of the fourth insulatinglayer is planarized to be substantially leveled with a top surface ofthe second magnetic pole prior to forming the second magnetic layer. 6.The method of manufacturing a thin film magnetic head according to claim5, wherein the second thin film coil is buried with the fourthinsulating layer and the top surface of the second magnetic layer isplanarized.
 7. The method of manufacturing a thin film magnetic headaccording to claim 1, wherein a first connecting portion is formed onthe first magnetic layer with a material making the first magnetic pole,simultaneously with formation of the first magnetic pole, and a secondconnecting portion is formed simultaneously with the second magneticpole, the second connecting portion having an area different than thatof the first connecting portion.
 8. The method of manufacturing a thinfilm magnetic head according to claim 1, wherein a width of the firstmagnetic pole facing the recording-medium-facing surface is formed widerthan that of the second magnetic pole.
 9. The method of manufacturing athin film magnetic head according to claim 1, further comprising a stepof forming a magnetoresistive element for reading out.